Since World War I, offshore disposal of unexploded ordnance (UXO) and discarded munitions has contaminated extensive areas of the world's coastal seas. Although seemingly 'out-of-sight and out-of-mind', this legacy UXO poses environmental and safety hazards. Corroding munitions release toxic compounds that harm marine ecosystems; meanwhile, many UXO retain active explosive potential, presenting direct risks to human life and maritime infrastructure. The long-term fate of these objects is governed by coastal dynamics and sediment regime. However, field-based understanding of their mobility and burial dynamics remains limited, particularly in wave-dominated, microtidal environments such as the Eastern Mediterranean. This study addresses this knowledge gap by characterizing munition transport and burial dynamics under varying hydrodynamic conditions on the sandy inner shelf of Israel. Dummy munitions of three size classes were deployed in standardized arrays along a shore-perpendicular transect (5, 10, and 15 m depth) offshore Rishon LeZion. Local waves and current gauges monitored environmental conditions, and selected dummies were equipped with accelerometers. Divers periodically documented munition position, displacement, and burial relative to initial deployment.
Results indicate that munition mobility is predominantly controlled by storm activity, with object mass the critical factor. Lightweight munitions exhibited movement in 100% of the measurements, compared to 67% of heavy items, with lighter munitions also exhibiting significantly greater displacement magnitudes. While deployment water depth did not affect displacement magnitude, it influenced direction; movement was generally eastward (shoreward), with shallow stations showing northward displacement while deeper stations showed southward displacement. Notably, munitions were found buried despite net seabed erosion, suggesting localized scour-induced self-burial and/or bed liquefaction rather than sediment accumulation. These findings provide new, field-based insights into post-disposal munition dynamics in the Eastern Mediterranean inner shelf, and will contribute to refining existing predictive models. Ultimately, this work supports evidence-based risk management for coastal safety and marine UXO clearance.